Light Waves Flashcards
What are some sources of light
Sun Stars Fire Torch Light Bulbs Fire Flies
What are luminous objects
These are objects that can emit their own light.
What are non-luminous objects
These are objects that cannot emit light but some non-luminous objects can reflect light. ex: the moon.
What is the law of reflection
The angle of incidence is equal to the angle of reflection.
What is refraction
When a light ray is entering a different medium, the light ray will slow down. This change in speed causes the light ray to change direction, which is called, “refraction”.
If a light ray strikes the medium at a right angle, the light ray will keep going straight without any refraction.
What is the refractive index
This is the amount a certain material can bend the light at.
What is the equation for the refractive index (Snell’s Law)
Refractive Index = sin i / sin r
What is a total internal reflection
When the light ray is traveling from a more optically dense medium to a less optically dense medium and the angle of incidence is greater than the critical angle the light ray will get reflected back into the more optically dense medium, because the interface between the 2 medium act as a reflective surface.
What is the equation for Critical Angle?
sin C = 1 / n
What are some uses for Total Internal Reflection
- Prismatic Periscope
- Prismatic Binoculars
- Optical Fibers
- Endoscopes
- Telecommunication
What are the requirements for total internal reflection to occur
- The light ray should be traveling from a more dense medium to a less dense medium
- The incident ray should be greater than the critical angle of the medium.
What is the Critical Angle
This is the smallest possible angle of incidence at which the light rays will get totally internally reflected.
